Question

I recently bought a phone from the US and I faced a unique problem with it. When I inserted my sim in
it, it showed me the error - 'No sim inserted'. I tried with multiple network sims but discovered that
none but Vozy network's sims work in it​

Answer 1

Answer: The phone must be a locked network Sim.

Explanation: In some Telecom companies the phones are being sold with network locked phones which means you can only use the particular sim which is provided by company like "Vozy network". So the phone is network locked by Vozy network.